Author Jeff Vande Zande was pleased when his latest book reached a digital milestone - it "went Kindle," formatted as an electronic book for Amazon.com's portable e-reader.

Although the college English professor from Michigan is hopeful about the new market his novel, "Landscape with Fragmented Figures," might reach, he isn't quite sold on electronic readers and still prefers the look, feel and "weathered page" smell of a printed book.

"Not all books are in Kindle edition, so for me, it was a big deal," Vande Zande said. However, he believes "the Kindle is not going to revolutionize books in the same way as the Internet and the iPod have revolutionized how we take in music."

Shoppers may be pondering whether to buy a handheld e-reading device this holiday season, but there's still a wide range of opinions about whether the devices mark the leading edge of the next digital media revolution or just another passing fancy.

For the concept of a device that allows books to be read electronically, "this is the year we get it," said Steve Portigal, the head of Pacifica consumer research firm Portigal Consulting. "But there's this huge psychological chasm we have to cross before people buy them."

Still, interest in e-readers seems to be growing, and some analysts say it is one of the hottest categories in consumer electronics.

Amazon's Kindle and Sony's Reader models led the way, but in recent months the buzz became louder. Barnes & Noble announced the Nook, which has run into shipping delays, while other e-readers are expected next year.

Mountain View's Google Inc., meanwhile, announced plans for Google Editions, which will offer between 400,000 to 600,000 electronic books to be read over any device that can connect to the Web, including e-readers.

The research firm In-Stat projects that 28.6 million e-readers will be shipped worldwide in 2013, up from 924,000 in 2008.

"I do think it has legs, serious legs," said In-Stat senior analyst Stephanie Ethier. "If the economy was better, I think we'd see better purchase rates than there are."

Record sales

Seattle's Amazon.com Inc. announced this week that sales of the Kindle, which starts at $259, hit a monthly high in November and has become the best selling product across all of the online retail giant's categories.

Amazon, however, did not disclose how many Kindles it sold. Allen Weiner, a research vice president for Gartner's Media Industry Advisory Service, estimates 600,000 Kindles have been sold since their introduction in 2007, based on available publishing industry numbers.

Bookseller Barnes & Noble, meanwhile, said it has already sold out of its $259 Nook, due to appear in its stores Monday, so new orders won't be shipped until at least Jan. 11.

The Kindle is also boosting electronic book sales. Amazon sells 48 Kindle books for every 100 physical books when both editions are available, up from 35 Kindle books per 100 in May.

"We are surprised that this number is so high this early on, given that we've been selling physical books for 15 years," said spokeswoman Cinthia Portugal.

Too early to tell

But Steve Portigal said it's too early to tell whether e-readers will change the way people read in the way MP3 players changed the way people listen to music. For one thing, people can jog, drive or do other things while listening to an iPod, but must concentrate on reading with an e-reader.

Steve Haber, president of Sony's Digital Reading Division, is firmly convinced that e-readers are the next wave of the transition of media from analog to digital. Haber remembers when people said they preferred the "warmth" of analog LP records to CDs or the quality of photographic film over digital images.

"When people use the device, they love it," Haber said. "Once you go digital, you don't go back to analog. I think in five years, more books will be sold in digital (form) than in physical."

Paperweights?

Others disagree.

"I think in two years, all of them are going to be paperweights," said Bob LiVolsi, chief executive and founder of BooksOnBoard Ltd., an Austin, Texas, company that is in the business of selling electronic versions of books.

The firm, the largest independent e-book seller with more than 400,000 titles, does sell Sony Reader, Cybook Opus and Astak EZ Reader models to customers. But LiVolsi, who once used the pioneering Rocket eBook, now prefers his versatile netbook, which costs about the same as a single-purpose device.

"A dedicated device, from a personal standpoint, is just an extra piece of hardware I would have to lug around," LiVolsi said. And the cost of an e-reader is "like a luxury car payment."

Gartner's Allen Weiner said netbooks still aren't widely used as e-readers, but it could eventually cut into the market. A rumored tablet computer from Apple could be a game changer, as could other e-readers expected to be introduced at the 2010 Consumer Electronics Show in January or beyond, Weiner said. Time Inc. this week even unveiled a video representation of a future Sports Illustrated tablet version.

Weiner said other potential problems for e-readers include the fact that publishers and devices makers have adopted different formats and that books from popular authors, including John Grisham and J.K. Rowling, aren't yet available in digital form because of royalty issues.

If some of these pieces fall into place, the holiday shopping season of 2010 might be big for e-readers, Weiner said.

Is it too early this year to buy an e-reader?

"If you must have an e-reader now, I say dive in," Weiner said. "If not, I say wait until the spring. There may be more choices if you're willing to wait until the phenomenon becomes less of a phenomenon and becomes more of a market."